Apparatus for protecting power-line insulators



Feb. 7, 1933. HIP. SLEEMAN AfiPARATUS-FOR PROTECTING POWER LINEINSULATORS Filed April 50. 1927 1 2 Sheets-Sht' 1 INVENTOR." HflROLD F.SLEEMHN BY W ATTORN EYS 1933- H. P. SLEEMAN 1,896,189

APPARATUS FOR PROTECTING POWER LINE INSULATORS Filed April 30, 1927 2Sheets-Sheet 2 cg N INVENTOR: HHR'OLD F. 54 EEMI-V/V ATTORNEYS.

Patented Feb. 7, 1933 UNITED STATES PATENT OFFICE HAROLD P. SLEEMAN, OFEAST LIVERPOOL, OHIO, ASSIGNOR TO THE R. THOMAS & SONS COMPANY, OF EASTLIVERPOOL, OHIO, A CORPORATION OF OHIO APPARATUS FOR PROTECTINGPOWER-LINE INSULATOBS Application filed April 30,

My invention relates to method and apparatus for protecting power lineinsulators, and particularly multi-unit insulators.

My invention contemplates the protection of the insulator againstunequal voltage stresses on the several units by better voltagedistribution over the insulator, the means employed for this purposebeing such that it does not interfere with live line lnsulator testingappliances.

My invention contemplates the protection of the insulator by providingboth a voltage distributor and also an arc-over path, in parallel withthe insulator, to protect the latter against injury by flash-over. Insuch a combination, my invention contemplates the location of thedistributor between the lineend of the arc-over path and the power line,so that on arc-over the arc plays not upon the voltage distributor butupon the arc terminal.

Again my invention contemplates, in this combination, a voltagedistributor of such construction that should an arc form thereon, it isautomatically led to the arc-over terminal.

My invention also contemplates, in this combination, the location of-thevoltage distributor closer to the insulator than the terminal at theline-end of the arc-over path, so that on arc-over the are forms at apoint more remote from the insulator than the voltage distributor.

From the standpoint of apparatus my in vention contemplates a combinedarc terminal and voltage distributor, the latter preferably in the ormof arcuate lateral extensions of the terminal and extending linewardfrom the terminal, and inward toward the insulator. A pair of suchcombined arc terminals and voltage distributors, when installed at theline-end of a multi-unit insulator, is so located that the arc-overterminals overlie the line conductor, while the arcuate terminalextensions which constitute the voltage distributors, substantiallysurround the lower portion of 'the insulator but are sospaced at theiradjacent ends as to permit the introduction of live line testingappliances to the insulator.

1927. Serial 1T0. 187,908.

Other features of my invention will be understood from the followingdescription, or from the accompanying drawings, in which Fig. 1 is abroken side elevation of a multiunit suspension insulator to which areapplied protecting devices which embody my invention in one form;

Fig. 2 is a plan view thereof;

Fig. 3 is an enlarged plan view of a combined arcing terminal andvoltage distributor;

Fig. 4 is a side elevation thereof;

Fig. 5 is a front elevation thereof;

Fig. 6 is a section on the line 6-6, Fig. 3;

gig. 7 is a section on the line 77, Fig. 3; an

Fig. 8 is a section on the line 8-8, Fig. 3.

It has been recognized (see Marvin 1,245,940) that in multi-unitinsulators the voltage stresses upon the several units of the insulatorare unequal, and that the voltage stress upon the units at the line endof the insulator materially exceeds that impressed upon the units at theopposite or ground end of the insulator. As a result of this condition,failure of the insulator by puncture occurs most frequently in the unitsadjacent the line. The introduction of metal discs of various dimensionsbetween the several units of the insulator to vary their capacities,effects a voltage distribution which renders more uniform the stresseson the several units. But this manner of accomplishing the desired endis objectionable since it increases the likelihood of flash-over on theinsulator surfaces (by reason of the reduction of the leakage path), andmoreover tends to cause an arc to cascade from arcing horns into theinsulator, thus increasing the prob-ability of damage thereto from theheat of the are.

My invention accomplishes the desired voltage distribution over theinsulator string by providing a source of line voltage substantiallysurrounding the line end of the insulator at a point spaced radiallytherefrom, the current from this source reaching the units remote fromthe line, and preventing the concentration of voltage stress upon theunit or units at the line-end of the insulator. This voltage distributoris of such construction that while substantially surrounding the lowerportion of the insulator, it permlts safe access to the insulator forthe application thereto of live line insulator testing appliances, suchas are now commonly used for field test. Preferably my invention isembodied in a voltage distributor which has combined therewith an arcingterminal, and the latter is preferably so located with respect to thevoltage distributor that arc-over is invited not to the distributor butto the arcing terminal. Preferably, furthormore, this terminal is ofsuch construction that the arc is caused automatically to move awa fromthe insulator. Danger that the are, a er formation, will strike into theinsulator, is thus minimized.

Referring to the accompanying drawings, I have indlcated in Fig. 1 amulti-unit suspension insulator of the link or Hewlett type, comprisinga string of insulator units 15, of which the lowest unit is connected byadapter 16 and hanger 17 to the power line P, while the top unit of thestring is connected by adapter 18 and hook 19 to a grounded tower orother supporting structure (not shown). Associated wlth the hanger 17and secured thereto by bolt 20, is a bar 21, the opposite ends 22 and 23of which are angled upward and are pierced at suitable points to receivethe bolts 24 by which the combined arcing terminals and voltagedistributors of my invention are attached thereto.

Each combined arcing terminal and voltage distributor comprises a shank25 channeled to fit the bar end 22 or 23 and apert-ured to accommodatesecuring bolts 24. At its free end the shank 25 is enlarged to form aspoon-shaped arcing terminal having a spheroidal surface 26 which mergesinto a contracted tip 27. This terminal is described and claimed in thecopending application of H. B. Vincent Serial No. 184,987, patented Aril 12th, 1932, Patent No. 1,854,083 an insofar as it is claimed thereinI make no claim to it here. This terminal has the characteristics of asphere or high speed gap at the area 26, and of a needle point gap atthe tip 27. U n arc-over, between one of these termina s and acooperating terminal at the ground end of the insulator, the arc strikesthe area 26 and automatically travels outward to the tip 27. The arethus moves away from the insulatorimmediately after its formation, andthe danger that the arc will strike into the insulator is minimized. Thespheroidal area 26 of the terminal is also thus protected against injuryincident to the play of an arc thereon. Inasmuch as the ratin of the gapis governed by the s acing o the line and ground terminals at t eiradjacent spheroidal areas 26, the protection of the latter againstinjury is of great advantage in stabilizing the rating of the gap sothat the latter may be set accurately for a given arc-over value, whichis maintained in spite of repeated arcovers. I

Associated with the arcin terminal and extending from opposite si esthereof are arcuate wings 28 and 29 which form the voltage distributorelement of the appliance. These wings join the terminal at a pointremoved from the crest of the spheroidal area 26 and preferably extendlineward therefrom, so that they do not invite the arc to strike thedistributor wings. The upward inclination of the wings automaticallycauses the arc, should one form on the distributor, to rise to thearcing terminal. The wings are also spaced radially from the insulator aless distance tlTan the arcin terminal. They are located substantial yat the level of the lowermost unit 15 of the insulator string, but theirosition will vary with the line voltage and the character of the unitswhich compose the insulator. The lo-i cation indicated in the drawingstherefore is merely illustrative of a single appro riate location forthe type of insulator use and at a given line voltage.

In cross section the wings 28 and 29 are preferably arched on a ratherlong radius with their convex faces toward the gap. Corona formation onthe distributor is thus minimized. A stifienin rib 30 may be pro-v videdon the concave ace of each wing to add to its rigidit It will be no thatbetween the ends of a pair of voltage distributors located as indicatedin Fig. 2, a space 31 is afi'orded through which a live-line testingappliance 31 through which the tester passes is lo-' cated at a pointremote from the line and in a plane substantially normal to the latter.

I have shown the voltage distributor applied only to the line end of theinsulator, while at the ground end of the latter an arcing horn 32 isprovided which, while having the characteristics of the terminal of thefitting at the line-end of the insulator, lacks the voltage distributorwings. If for any reason desired, however, the distributor fit- {ing maybe used at both ends of the insuator.

It will be understood further that the invention is not restricted inits utility to multiunit insulators of the link or Hewlett typeillustrated 1 and 2, but is equally applicable to insulators of the capand pin t pe, or to multi-unit post insulators. I .use t e expressionmulti-unit insulator therefore in a sense broad 'eno'ugh'to include anytype of insulator in which; the '.problem of V0 tage distribution is oneof 1II1POIt8J1CC.

It will be understood furthermore that Whether or not thevoltagedistributor has associated therewith an arcing terminal'of thetype indicated, it possesses features of novelty and advantage which arenot dependent upon the combined use therewith of an arcing terminal ofthe type shown. Certain of the claims which point out my invention arenot restricted to this combined structure.

The details of contour and arrangement of parts are subject to widevariation, while still embodying the thoughts which underlie what Iclaim as my invention.

I claim- 1. A fitting for a multi-unit power-line insulator comprisingarcuate conductors adapt-. ed to be connected to the line and extendaround the line-end of the insulator to form a voltage distributor, saidconductors having associated arc-gap terminals whereby arcing over thesurface of the insulator units is prevented.

2. A fitting for a multi-unit power-line insulator comprising arcuateconductors adapted to be connected to the line and extend around theline-end of the insulator, said conductors having associated arc-gapterminals spaced radially more remote from the insulator than thevoltage distributor.

3. A combined arc-gap terminal and voltage distributor for multi-unitpower-line insulators, comprising a high speed gap terminal and avoltage distributor at one side thereof, said distributor comprisingarcuate extensions from said terminal.

4. A combined arc-gap terminal and voltage distributor for multi-unitpower-line insulators, comprisin a high speed gap terminal and associatearcuate voltage distributor extensions on opposite sides thereof, saidextensions having convex surfaces faced toward the gap.

5. A combined arc-gap terminal and voltage distributor for multi-unitpower-line insulators, comprising a spoon-shaped gap terminal andvoltage distributor wings extending from opposite sides of the terminal.

6. A combined arc-gap terminal and voltage distributor for multi-unitpower-line insulators, comprising a spoon-shaped gap terminal andvoltage distributor wings extending from opposite sides of the base ofthe terminal.

7. A combined arc-gap terminal and voltage distributor for a multi-unitpower-line in- 1 tributor adjustably connected to said support,

for va ing the position of the 'di'stn utor in the irection of the axisof the insulator.

8. In combination, a multi-unit power-line.

whereof I have signedm) CERTIFICATE OF CORRECTION.

Pmm No. 1,896,189. February 7, 193a.

HAROLD P. SLEEMAN.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 3,line 33, claim 2, after "insulator" and before the comma, insert thewords "to form a voltage distributor"; and that the said Letters Patentshould be read with this correction therein that the same may conform tothe record of the caae in the Patent Office.

Signed and sealed this 9th day of May, A. D. 1933.

M. J. Moore (Seal) Acting Cormnissioner of Patents.

